Projectile



2 Sheets-Sheet 1 INVENTORS. George. W. Blackinton.

John J. Calhoun. BY M I ATTORNEY May 11, 1948- G. w. BLACKINTON ET AL PROJECTILE Filed Aug. 19, 1942 May 11, 1948. s. w. BLACKINTON ET AL 2,441,388

PROJECTILE Filed Aug. 19, 1942 2 Sheets-Sheet 2 INVENTORS ew. Blnckinton John J. Calhoun ATTORNEY PRQJEC'EILE George W. Blackinton and John J. Calhoun,

Philadelphia, Pa, assignors, by mesne assignments, to the United States of erica Application August 19, 1942, Serial No. 455,323 1 Claim. (o1. 1102-56) barrels or the like and usually known as rifl grenades.

In the type of grenade here under consideration an explosive charge is carried in a suitablecasing connected at one end to a tube arranged to fit over a rifie barrel or the like and to be projected therefrom by firing a blank cartridge in the rifle. The grenade charge may be exploded by a suitable firing mechanism actuated by impact of the grenade upon the target.

An object of this invention is to provide a projectile of this type constructed and arranged to embody a greater explosive power and destructive capacity for a given size of projectile than has heretofore been achieved, so far as we are aware. A further object is to provide a rifle grenade of such design as to be capable of quantity produc tion in large volume by conventional'manufacturing operations.

A further object is to provide an armor piercing projectile of the grenade type constructed and arranged to have the maximum destructive effect upon the target.

These and other objects are attained by the invention hereinafter described in connection with the accompanying drawings in which:

Fig. 1 is a view partly in longitudinal'section and partly in elevation of a rifle grenade constructed in accordance with one embodiment of this invention;

Fig. 2 is a view of a grenade similar to that shown in Fig. 1 but arranged for practice only, the explosive charge and firing mechanism being omitted;

Fig. 3 is a transverse sectional view on line 3--3 of Fig. 1;

Fig. 4 is a similar view on the line 4-4 of Fig. 1;

Figs. 5 and 6 are perspective views of the sheet metal casing and a collar member, respectively, prior to the assembly thereof;

Figs. '7 and 8 are sectional views thereof showing certain steps in the assembly thereof; and

Fig. 9 is a section on the line 9-9 ofFig. 8.

As illustrated in Figure l, the. present invention is shown in connection with a rifle grenade having a casing lil formed by a sheet metal stamping for holding an explosive charge H. The rear end of the casing is curved inwardly and providedgonal opening with the roughened face 5 pressed against the end of the casing. In assembling, the extension 6 is spun outwardly to clamp the end of the casing against the roughened face 5. In the spinning operation the metal of the extension 6 expands into the corners of the hexagonal opening 4 and locks the collar and container against relative rotation. After the spinning operation, in order to eliminate any possible play between the parts, the material of the extension 6 which has been spun over against the rear face of the container is clinched at spaced intervals I. After the assembling operation the collar 3 is provided with internal threads 8. A fuse assembly is provided including a body member I4 having an annular threaded projection l5 for engagement with the collar 3 and extending outwardly from the casing so as not to obstruct the interior thereof. The body member is provided with a closed-end bore 86 in which a firing pin'll having a firing point it is slldably mounted and normally pressed against the closed end of the bore by a coil spring is located between the firing pin and a detonator cup 25 threaded in the open end of the bore. A. booster charge 22 is also threaded in the outer end of the bore which is closed thereby.

A stabilizer assembly including a sheet metal tube 23 is secured to the outer reduced end at of the fuse assembly body member M by four sheet metal drive screws 25 and spot welds 25'. The outer end of the tube 23 is provided with a plurality of stabilizer fins 26 for stabilizing the projectile in flight. As illustrated, each fin is spot welded to the outer face of the tube and extends radially outward therefrom. Each fin is then bent to form a circumferential section 2'! concentric with the tube '23 and extending circumferentially to the adjacent fin 26, being spot welded to a depression 28 formed therein. resulting stabilizer surfaces include the radial fins and an outer, connecting, circumferential ring 29. As illustrated, three fins and circumferential sections complete the assembly.

The firing pin is normally locked against movement. The lock shown consists of a flexible safety or locking pin 3i extending through a hole 32 in the body member l4 and engaging in a groove 33 in the firing pin I I. The' locking pin is flexible and is preferably bent so as to extend for a short distance longitudinally of the tube 23 and then circumferentially thereof a distance sufflcient to snap around the stabilizer of the safety pin preferably projects in the manaccuse ner shown so as to be easily seized. In this construction it will be noted that the safety pin forms an integral part of the fuse assembly and is entirely separated from the explosive charge.

In order to gain full advantage of the increased shattering eflect produced by an explosive charge when the surface facing the target is concave in form, the present invention comprises a cone 35 of pressed sheet metal having a circumferential flange 36 at the base thereof engaging the forward end of the casing ill, the cone extending into the explosive charge for a distance, in the illustrated embodiment, slightly more than onehalf the length 01' the casing, thus leaving a substantial column of explosive between the apex of the cone and the opposite end of the casing. The cone is also secured in position by an ogive 31, also of pressed sheet metal, which extends forwardly from the casing and which is secured thereto by having the end 38 spun into the groove 39 formed in the outer face of the casing adjacent the forward end thereof. The ogive is provided with a plurality of circumferentially spaced indentations 4| positioned so as to engage flange 38 of the cone and press it firmly into position against the end of the casing l0.

Fig. 2 illustrates the grenade of Fig. 1 modified for practice purposes without any explosive being present. a In this construction an and plug 42 is threaded into the collar l2 and has a barshaped extension 43 which projects forwardly into the casing in a sufllcient distance to provide the weight and balance characteristics or a loaded grenade. Also. the cone 35 is omitted and the ogive 31 is connected to the casing III in the manner described in connection with Fig. 1 but without the cone being interposed between the easing and the ogive.

In firing a grenade, the safety pin 3| is first untwisted by bending it into the dotted line position shown in Figs. 1 and 4, and then extracted to ifree the firing pin. The grenade is then placed over the end of a rifle barrel. Upon firing a blank cartridge in the rifle the grenade is propelled at high velocity against the target. Upon impact the ogive is crushed and the flring pin projected forwardly to explode the detonator 2| and booster charge 22, in turn exploding the charge I l in the casing l0.

An important part of the present invention lies in the relative dimensions of certain parts. We have discovered that the relative length of the ogive has a direct bearing upon the effectiveness of the explosion of the charge ll. That is to say, the distance from the head or point of the ogive to the head of the bodyof the projectile, commonly spoken of as "the base of the cone." is critical. We have determined that for a flxed velocity of projectile and a certain brizance (rate of propulgation of the explosive charge), a certain length of ogive is required for maximum destructive effect. This length should be such that the base of the cone is spaced from the surface of the target at the time of detonation. Obviously the time of firing is subject to control by the length of the ogive. Likewise, the destructive eflect is increased by lengthening the column of explosive between the apex of the cone 3! and the opposite end of the casing ll, up to a cerl tain maximum dimension of approximately eight inches. For example, with the proper dimensions the explosion will not only shatter armor plating, but will cause the cone 36 to penetrate such Plating as a Projectile.

By providing for rear end detonation, it will be apparent that the present construction will produce a straight line explosion wave traveling .the firing assembly body member by four driven fasteners and spot welds, and the two subassemblies are connected together by threading the body member into the collar 13. Obviously, the

invention can be variously modified and adapted within the scope of the appended claim.

, What is claimed is:

An explosive projectile comprising in combination an annular casing for holding an explosive charge, said casing having at least one open end and a peripheral recess in the external surface thereof a jacent said open end, a charge retaining cone within said open end and having a pcripheral flange in engagement with the transverse face of said open end, and a sheet metal ogive surrounding said open end and having a circumferentially spaced series of radially inwardly oflset portions, the offset portions of said series engaging said flange, said ogive having a peripheral flange in engagement with said peripheral recess, whereby said ogive retains said cone and said casing in fixed relation to each other and to itself.

GEORGE W. BLACKINTON. JOHN J. CALHOUN.

REFERENCES CITED The following references are of record in the file of this patentz' UNITED STATES PATENTS Number Name Date 549,072 Maxim Oct. 29, 1895 1,105,849 Semple Aug. 4, 1914 1,183,503 Stout May 16, 1916 1,293,869 Murray et a1 Feb. 11, 1919 1,316,296 Gathmann Sept. 16, 1919 1,416,662 Brondy May 16, 1922 1,521,996 Ciano Jan. 6, 1925 1,539,609 Taylor May 26, 1925 1,900,790 Brandt Mar. 7, 1933 2,108,818 Hufi! Feb. 22, 1938 2,419,414 Mohaupt Apr. 22, 1947 FOREIGN PATENTS Number Country Date 28,030 Great Britain Dec. 13, 1911 103,589 Great Britain Feb. 1, 1917 507,795 France July 5, 1920 113,685 Australia Aug. 14, 1941 

